If hotels do a virtual buffet and other nonsense I'll just opt out and grab some bits from a local supermarket, which I imagine is what they really would like - to eliminate breakfast entirely.

Just like making room service opt in - they can claim it's available but obviously a lot of people just don't bother because they pick up on the signal from the hotel that they don't want to do it

Personally I've never seen wasteful people at breakfast buffets in the UK. Greedy yes but not plates of unfinished food.

It's also good to remember how much breakfast regularly costs now. £15-20 is quite common at mid range places - £10 of yesteryear is exceedingly rare